Conjugation of insulin-mimetic [meso-tetrakis(4-sulfonatophenyl)porphyrinato]zinc(II) with chitosan in aqueous solution: kinetics, equilibrium and thermodynamics

Enhanced photocatalytic degradation of crystal violet and malachite green oxalate dyes by NiAg2O infused chitosan nanocomposites

The present study investigated the catalysis of Lupeol-loaded chitosan nanoparticles infused with NiAg2O nanoparticles to create a NiAg2O/Lup@CS nanocomposite. Recent advances in nanomaterials with unique architectures and functionalities have successfully treated contaminated soil and industrial wastewaters. Consequently, a lupeol@chitosan nanoparticle loaded with NiAg2O was created, and its catalytic effectiveness in degrading industrial dye pollution was examined. The ionic gelation synthesis route was used to produce the NiAg2O/Lup@CS nanocomposite. After that, the resultant nanocomposite underwent extensive analysis to determine its elemental composition through EDAX, surface bonding, nature, crystallinity using FTIR, FESEM, and XRD, and powdered particle size using HRTEM. Subsequently, the produced nanocomposite's efficacy in photo-catalytically degrading Crystal violet and Malachite green oxalate were evaluated. Moreover, the Crystal violet and Malachite green oxalate degradation kinetics were studied using the Langmuir-Hinshelwood model, which also offered a plausible photocatalytic process. The catalytic mechanism suggested that the addition of Lup@CS nanoparticles would have had the effect of speeding up photocurrent transport by increasing the quantity of electrons and holes produced by the photon's irradiation. This highlights the significance of creating innovative composite photocatalysts. The study also observed the superior photocatalytic activity of NiAg2O/Lup@CS nanocomposite with 86.14 % degradation of Crystal violet and 86.65 % degradation of Malachite green oxalate.

Efficient adsorptive removal of levofloxacin using sulfonated graphene oxide: Adsorption behavior, kinetics, and thermodynamics

Water pollution by antibiotic residues poses a potential threat to environmental and human health. Graphene-based materials are highly stable, recyclable and effective adsorbents for efficiently removing antibiotics from polluted water. In this study, the adsorption behavior of levofloxacin onto sulfonated graphene oxide (SGO) was investigated by varying the contact period, solution pH, adsorbent quantity, levofloxacin concentration, inorganic ions, and solution temperature. Spectroscopic and microscopic techniques were employed to confirm the adsorptive interaction between levofloxacin and SGO. The adsorption process was most accurately characterized by the pseudo-second-order kinetic model and the Langmuir isotherm model, as indicated by their high correlation coefficients (R 2) and low root-mean-square error (RMSE) values. The maximal quantity of levofloxacin that can be adsorbed onto SGO was determined to be 1250 μmol/g at pH 4 and 25 °C using the Langmuir model. Thermodynamic studies reveal that the process of levofloxacin adsorption onto SGO is endothermic and spontaneous in nature. Taking into consideration the results of adsorption, desorption and regeneration studies, it is proposed that SGO can be applied as an economic viable agent for the adsorptive removal of levofloxacin from the aqueous environment.

The role of macrocycles in supramolecular assembly with polymers

Recently, supramolecular self-assembly has attracted the attention of researchers worldwide because it enables the creation of nanostructures with unique properties without additional costs. Spontaneous organization of molecules allows the design and development of new nanostructures that can interact with drugs and living cells and generate a response. Therefore, supramolecular structures have enormous potential and can be in demand in various fields of healthcare and ecology. One of the widely used building blocks of such supramolecular assemblies is polymers. This review examines the joint aggregation behavior of various macrocycles (cyclodextrins, calixarenes, cucurbiturils, porphyrins, and pillararenes) with polymers, the functional properties of these supramolecular systems and their potential applications.

Kinetics, Equilibrium, and Thermodynamics for Conjugation of Chitosan with Insulin-Mimetic [meso-Tetrakis(4-sulfonatophenyl)porphyrinato]oxovanadate(IV)(4-) in an Aqueous Solution

This study investigated the conjugation of chitosan with the insulin-mimetic [meso-tetrakis(4-sulfonatophenyl)porphyrinato]oxovanadate(IV)(4-), VO(tpps), in an aqueous medium as a function of conjugation time, VO(tpps) concentrations, and temperatures. To validate the synthesis of chitosan-VO(tpps) conjugate, UV-visible and Fourier transform infrared spectrophotometric techniques were utilized. Conjugate formation is ascribed to the electrostatic interaction between the NH3+ units of chitosan and the SO3- units of VO(tpps). Chitosan enhances the stability of VO(tpps) in an aqueous medium (pH 2.5). VO(tpps) conjugation with chitosan was best explained by pseudo-second-order kinetic and Langmuir isotherm models based on kinetic and isotherm studies. The Langmuir equation determined that the maximal ability of VO(tpps) conjugated with each gram of chitosan was 39.22 μmol at a solution temperature of 45 °C. Activation energy and thermodynamic studies (Ea: 8.78 kJ/mol, ΔG: -24.52 to -27.55 kJ/mol, ΔS: 204.22 J/(mol K), and ΔH: 37.30 kJ/mol) reveal that conjugation is endothermic and physical in nature. The discharge of VO(tpps) from conjugate was analyzed in freshly prepared 0.1 mol/L phosphate buffer (pH 7.4) at 37 °C. The release of VO(tpps) from the conjugate is a two-phase process best explained by the Higuchi model, according to a kinetic analysis of the release data. Taking into consideration all experimental findings, it is proposed that chitosan can be used to formulate both solid and liquid insulin-mimetic chitosan-VO(tpps) conjugates.